Generally, a road that is prepared for driving of vehicles is constructed using a material such as asphalt, concrete or the like, and various types of road surface markings for guiding driving of vehicle drivers, as well as lines for dividing driving paths, are formed on the road surface. At this point, the road surface markings include turn-left, turn-right and go-straight arrows, markings of destination names, speed limit markings, crosswalk markings and the like.
Although vehicle drivers reach a destination with the help of the road surface markings and road signs like this in the past, recent vehicle drivers drive with the guidance of a navigation device installed in a vehicle to further quickly and conveniently reach the destination. A general navigator provided with a display implements various functions, such as guiding routes to a destination, alarming speed limits, displaying rest areas and gas stations and the like, for comfortable driving of a vehicle driver.
However, since the navigator is merely an apparatus which recognizes a road as a simply line and guides a route on the basis of a map, it may not provide intuitive guidance on a state of a road. For example, when traffic lanes or road surface markings are erased and difficult to identify or roads are damaged to have cracks or potholes, if the drivers rely only on the navigator, the risk of occurring an accident may greatly increase due to the bad condition of the roads. Accordingly, a system that can also provide practical guidance on the road states, in addition to simple guidance on the routes using the navigator, is required to solve the problem.